From America's Test Kitchen Season 2: Peach Pie
Fresh peach pies are often soupy or overly sweet, with a bottom crust that is soggy or undercooked. We wanted to create a filling that was juicy but not swimming in liquid, its flavors neither muscled out by spices nor overwhelmed by thickeners, and we wanted a crust that was well browned on the bottom.
We peeled and sliced the peaches and found that all they needed in the way of flavor was sugar, lemon juice, cinnamon, nutmeg, and a dash of salt. To thicken the juices, we used a little cornstarch, but still, we needed to do more. A lattice-top pie crust was our solution—while it requires a bit more work than making a regular double-crust pie, we found that it’s worth the effort. Not only is it pretty and very traditional on peach pies, but it serves an important purpose: The structure of a lattice top allows for maximum evaporation while the pie cooks—the juices released by the fruit cook down slowly while baking so the filling isn’t soupy. For easy assembly, we rolled and cut the dough, then froze it so the strips were firm and easy to handle.
If your peaches are larger than tennis balls, you will probably need 5 or 6; if they’re smaller, you will need 7 to 8. Cling and freestone peaches look identical; try to buy freestones, because the flesh will fall away from the pits easily. Potato starch can usually be found in the Kosher section of the supermarket. If you don’t have or can’t find potato starch, substitute an equal amount of pulverized Minute tapioca. Serve the pie with vanilla ice cream or whipped cream. See illustrations below for Peeling the Peaches and Weaving and Crimping the Lattice Top.